Agenda item

Report of the Interim Executive Director, Environment.

Members received a report of the Interim Executive Director, Environment which sought approval to progress the Phase 4 SuDS (Sustainable Urban Drainage) for the Climate Resilience workstream.

An Officer introduced the report. She stated that this work was part of the Cool Streets and Greening Programme which consisted of four phases. Phases 1-3 were underway. Phase 4 was challenging due to the number of utilities underground, especially under the pavements.

The Officer informed Members that the original plan had been to implement 10 sites. To date, space had been found for 6 sites. Officers recommended taking these six sites forward and continuing to investigate other sites concurrently.

The Officer advised that most of the projects included sustainable drainage and rain gardens in the former carriageway, as the pavement was congested with utilities. At the site in St Andrew Undershaft, work was taking place with the church to introduce sustainable drainage, including capturing rainwater from the roof.

The Chairman commented that only 6 sites had been identified and asked if Officers were confident that more sites could be found. He also asked for more information on the scope of where these schemes could be implemented and whether they could be located in parts of the City liable to flooding. An Officer stated that the SuDS being proposed were primarily preventative, slowing the flow of water getting into the sewer and to some extent diverting that water from reaching the sewer. He explained that the difficulty with placing these schemes in flooded areas was that they were already full of water so they were not benefiting from the slowing down of water. Therefore, in flooded areas, to avoid potential damage, resilience measures such as traditional flood defences were more appropriate.

The Officer stated that the schemes were quite small so had to be spatially dispersed. The sites chosen primarily sat on the hill that ran down to the River Thames where there was surface water flooding and where the water flowed most quickly, in order to intercept this before it reached the place that was flooded.

Members were informed that in the City, a significant contributor to flooding was sewer flooding. Locating green SuDs in areas where there was sewer flooding made cleaning up afterwards more difficult as it was not just hard surfaces being cleaned.

The Officer informed the Sub-Committee that the team would be looking to identify more sites and would be targeting kerbside space.

A Member stated that he was disappointed that more greening of the streetscape had not taken place in recent years. He commented that this would improve the streetscape and also soak up water.

The Chairman referred to instances of flooding in the summer during thunderstorms which were a result of sewers being unable to cope with the volume of water and not as a result of saturated land. He queried whether, even though the clean-up would be more difficult, putting SuDS there could assist. The Officer stated that where there was sewer flooding, the water was coming from as far away as Wormwood Scrubs. The project sought to prioritise areas where the City contributed to the water going into the whole system so that the water flooding out in the City was minimised. He added that there was more benefit in doing this in areas which were not flooded because although these flooded areas were, by being flooded, slowing down thewater and holding it, these were not places that should be holding water.

RESOLVED – That Members of the Sub-Committee

1.         Approve the additional budget of £95,000 to reach the next Gateway, funded from the Cool Streets and Greening Programme (OSPR);

2.         Approve the revised total estimated cost range for this Phase (excluding risk) of £1.4m - £1.7m;

3.         Delegate approval of the Costed Risk Provision to the Chief Officer if one is sought at Gateway 5;

4.         Approve the statutory consultation on the proposed relocation of parking bays as set out in this report;

5.         Authorise officers to enter into an agreement with the Church to enable the St Andrew Undershaft churchyard works to proceed.

6.         Note that two of the sites (Ludgate Broadway and St Andrew Undershaft) include additional repaving and public realm enhancements that are to be funded by ring-fenced S106 funds that have been allocated to the projects and this will be detailed in future Gateway reports.

7.         Note that the sites at Ludgate Broadway and Lloyds Avenue will require further design work and will be the subject of a future Gateway 4 report in early 2024.

8.         Note that the underspend from this Phase will be redirected to Phase 3 of the programme to further progress tree planting, relandscaping for climate resilience and climate resilient planting. This will be formalised in a forthcoming programme update report in early 2024.